1. Field of the Invention
The present invention relates to a foreign object insertion detector device which is applied to a car power window device.
2. Description of the Related Prior Art
Conventionally, as a foreign object insertion detector device to be applied to a car power window device, there are known the following foreign object insertion detector devices.
That is, as a first conventional foreign object insertion detector device, there is known a foreign object insertion detector device which detects the insertion of a foreign object according to whether there is present an excess current or not which flows in a motor used to drive, that is, open and close the windowpane of a car window.
Also, as a second conventional foreign object insertion detector device, there is known a foreign object insertion detector device in which a soft tube body filled with transparent liquid of a high refractive index and formed of elastic material having a lower refractive index than that of the transparent liquid is implanted into a weather strip and, on both sides of the soft tube body in the longitudinal direction thereof, there are disposed a light emitting element and a light receiving element (Japanese Patent Publication No. 58-26621 of Showa). In the present insertion detector device, the light emitted from the light emitting element disposed on one end side is allowed to enter the transparent liquid serving as a core so that, while the light is being reflected totally by the inner peripheral surface of the soft tube body, the light is transmitted to the other end side and is received by the light receiving element; and, based on variations in the quantity of the light received by the light receiving element, the insertion of a foreign object can be detected.
In other words, in this conventional detector device, if there occurs any foreign object insertion and the soft tube body is elastically deformed due to a pressing force given from the foreign object, then the angle of incidence of the light entering the inner peripheral surface of the elastically deformed portion of the soft tube body varies; and, due to this, most of the light transmitted through the transparent liquid is changed in the advancing direction thereof and thus the light is caused to enter the inner peripheral surface of the soft tube body at the angle of incidence lower than or equal to a critical angle where the total reflection of the light occurs, with the result that the light is caused to leak outside the transparent liquid which serves as a guide path for the light. That is, the present detector device detects a decrease in the quantity of the received light of the light receiving element caused by the above-mentioned leakage of the light to thereby be able to detect the insertion of the foreign object.
However, in the above-mentioned first conventional foreign object insertion detector device, in order to prevent the foreign object insertion detector device from malfunctioning due to an excess current flowing in the motor when closing the windowpane tightly, the foreign object insertion preventive function of the detector device must be removed shortly before the windowpane is closed completely, with the result that the insertion preventive condition up to the time when the windowpane is closed completely cannot be secured positively.
Also, since the first conventional foreign object insertion detector device detects the insertion of a foreign object by detecting an excess current which is caused to flow when a load of a reference value or larger is applied to the motor, if the reference value is set too low, then there is a possibility that the presence of a foreign object insertion can be detected in error although no foreign object insertion exists actually. In order to prevent such erroneous detection, the reference value cannot be set excessively low. However, if the reference value is set rather high, then the detecting sensitivity is lowered accordingly. Therefore, when an operator""s hand or the like is caught between the car window and the windowpane, a great force can be applied to the hand.
On the other hand, in the above-mentioned second conventional foreign object insertion detector device, since the transparent liquid must be enclosed into the soft tube body, the structure of the soft tube body is made complicated, which results in the expensive manufacturing cost of the soft tube body.
Also, in order to be able to detect the insertion of a foreign object before a great force from the motor is given to the foreign object, preferably, the soft tube body may be elastically deformed easily by a relatively small pressing force. However, in the second conventional foreign object insertion detector device, since the transparent liquid must be enclosed with a certain level of constant pressure, if the hardness of the soft tube body is set too low, then there is a possibility that the soft tube body can be caused to swell more than necessary or the soft tube body can be deformed due to the weight of the transparent liquid too much to keep its shape. Therefore, the soft tube body must be so set as to have hardness equal to or higher than a given level of hardness, which unfavorably results in the poor detecting sensitivity of the pressing force from the foreign object.
Further, since the soft tube body is structured such that it encloses the transparent liquid therein, there is no space for the internal pressure thereof to escape and thus, when the pressing force from the foreign object is applied to the soft tube body, the internal pressure of the soft tube body increases in proportion to an increase in the pressing force applied from the foreign object; that is, as the pressing force from the foreign object increases, the repulsive force of the soft tube body against the pressing force from the foreign object increases. Therefore, the soft tube body with the transparent liquid enclosed therein is difficult to deform when an external pressing force is applied thereto, which also provides a factor in lowering the detecting sensitivity of the pressing force from the foreign object.
Still further, there is also found a problem that it is difficult to keep the reliability of the sealed enclosure of the transparent liquid for a long period of time.
Yet further, when water is used as the transparent liquid, the water can be frozen depending on the using temperatures thereof, which causes the light to be scattered within the light guide path, with the result that the foreign object detector device using the water can fail to function.
In addition, normally, the elastic material that is used to form the soft tube body has a low degree of crystallinity in the using temperatures (xe2x88x9240xc2x0 C.-+100xc2x0 C). Therefore, the elastic material is easy to swell by the liquid that is enclosed in the soft tube body, or some of the elastic material is easy to deteriorate in quality.
The present invention aims at eliminating the drawbacks found in the above-mentioned conventional foreign object insertion detector devices. Accordingly, it is an object of the invention to provide a foreign object insertion detector device which is simple in structure, can be reduced in the manufacturing cost thereof, is highly reliable, is able to detect a pressing force from a foreign object with high sensitivity, and is also able to detect even the insertion of the foreign object occurring just before the windowpane is closed completely.
As technical means for attaining the above object, according to the invention, there is provided, for use in a car power window device in which a car window can be opened and closed as a windowpane is driven or opened and closed by a drive mechanism under the control of a given control part, a foreign object insertion detector device for detecting the insertion of a foreign object between the car window and the windowpane when the car window is closed by the windowpane, the foreign object insertion detector device comprising: a weather strip disposed in the car window and including, in the inner peripheral portion thereof opposed to the closing-direction downstream side end portion of the windowpane, a light transmitting cavity portion extending along the longitudinal direction of the inner peripheral portion and communicating with the outside; pressing means disposed at least on one of the obliquely downward car exterior side and obliquely downward car interior side of the light transmitting cavity portion in the weather strip and, on receiving a pressing force given thereto from an obliquely downward direction with respect to the opening and closing direction of the windowpane, for deforming the light transmitting cavity portion in such a manner that it is crushed;
light emitting means for emitting a given light into the light transmitting cavity portion from one side of the longitudinal direction of the light transmitting cavity portion; light receiving means for receiving the light emitted by the light emitting means, reflected by the inner peripheral surface of the light transmitting cavity portion and transmitted to the other side of the longitudinal direction of the light transmitting cavity portion; and, judging means for monitoring one by one the quantities of the light received by the light receiving means, and also, on detecting a decrease in the quantity of the received light of the light receiving means caused when the weather strip is elastically deformed by a pressing force from said foreign object and the light transmitting cavity portion is thereby deformed in a crushing manner, for judging the presence of the insertion of the foreign object.
Preferably, the pressing means may comprise: a first cavity portion formed on the obliquely downward car exterior side of the light transmitting cavity portion in the weather strip in such a manner that it extends along the longitudinal direction of the light transmitting cavity portion; and, a first projecting portion which is provided on the obliquely downward car exterior side inner peripheral surface of the first cavity portion in such a manner that it extends along the longitudinal direction of the first cavity portion, and also which is capable of deforming the light transmitting cavity portion.
Also, preferably, the pressing means may comprise: a second cavity portion formed on the obliquely downward car interior side of the light transmitting cavity portion in the weather strip in such a manner that it extends along the longitudinal direction of the light transmitting cavity portion; and, a second projecting portion which is provided on the obliquely downward car interior side inner peripheral surface of the first cavity portion in such a manner that it extends along the longitudinal direction of the second cavity portion, and also which is capable of deforming the light transmitting cavity portion.
Further, preferably, the pressing means may comprise: third and fourth cavity portions respectively formed on the obliquely downward car exterior side of the light transmitting cavity portion in the weather strip in such a manner that they extend along the longitudinal direction of the light transmitting cavity portion at a given distance substantially in the vertical direction; and, a portion of the weather strip situated between the third and fourth cavity portions and acting as a pressing portion for deforming the light transmitting cavity portion.
Still further, preferably, the pressing means may comprise: fifth and sixth cavity portions respectively formed on the obliquely downward car interior side of the light transmitting cavity portion in the weather strip in such a manner that they extend along the longitudinal direction of the light transmitting cavity portion at a given distance substantially in the vertical direction; and, a portion of the weather strip situated between the fifth and sixth cavity portions and acting as a pressing portion for deforming the light transmitting cavity portion.
Yet further, preferably, the pressing means may comprise: a corner portion of the weather strip provided on and projected from the light transmitting cavity portion toward at least one of the obliquely downward car exterior side and obliquely downward car interior side.
And, preferably, the inner peripheral surface of the light transmitting cavity portion may be coated with a given light reflecting member for reflecting said light.
Also, preferably, the light transmitting cavity portion may be formed by implanting a hollow tube body formed of a given elastic material into the weather strip.
Further, preferably, the light transmitting cavity portion may be formed by forming a cavity in the weather strip itself.
As another technical means for attaining the above object, according to the invention, there is provided, for use in a car power window device in which a car window can be opened and closed as a windowpane is driven or opened and closed by a drive mechanism under the control of a given control part, a foreign object insertion detector device for detecting the insertion of a foreign object between the car window and the windowpane when the car window is closed by the windowpane, the foreign object insertion detector device comprising: a hollow tube body formed of light transmissive elastic material and implanted in a portion of the inner peripheral portion of a weather strip disposed in the car window, which is situated opposed to the closing-direction downstream side end portion of the windowpane, in such a manner that it extends along the longitudinal direction of the weather strip inner peripheral portion, with an internal space of the tube body being structured such that it communicate with the outside; pressing means disposed at least on one of the obliquely downward car exterior side and obliquely downward car interior side of the tube body in the weather strip and, on receiving a pressing force given thereto from an obliquely downward direction with respect to the opening and closing direction of the windowpane, for deforming the tube body in such a manner that it is crushed; light emitting means for emitting a given light into at least one of the internal space and the tube body from one side of the longitudinal direction of the tube body; light receiving means for receiving the light emitted by the light emitting means, transmitted through at least one of the internal space and the tube body, and transmitted to the other side of the longitudinal direction of the tube body; judging means for monitoring one by one the quantities of the light received by the light receiving means, and also, on detecting a decrease in the quantity of the received light of the light receiving means caused when the weather strip is elastically deformed by a pressing force from the foreign object and the tube body is thereby deformed in a crushing manner, for judging the presence of the insertion of the foreign object.
Also, preferably, the light emitting means may emit the light into the tube body from the above-mentioned one side of the longitudinal direction of the tube body, and the light receiving means may receive the light emitted by the light emitting means, transmitted through the tube body, and transmitted to the other side of the longitudinal direction of the tube body.
The present disclosure relates to the subject matter contained in Japanese patent application No. Hei. 11-028785 (filed on Feb. 5, 1999) which is expressly incorporated herein by reference in its entirely.